Blue Whale

Blue Whale

Mammalia

SCIENTIFIC CLASSIFICATION

COMMON NAME:

blue whale, sulpher-bottom

KINGDOM:

Animalia

PHYLUM:

Chordata

CLASS:

Mammalia

ORDER:

Cetacea

SUBORDER:

Mysticeti

FAMILY:

Balaenopteridae

GENUS SPECIES:

Balaenoptera musculus

FAST FACTS

DESCRIPTION:

Blue whales, named for their bluish-gray coloration, are known for their immense size. Their coloration often includes grayish or whitish areas. When viewed from above, the rostrum appears broad and U-shaped and a large splashguard surrounds two blowholes. A blue whale's slender, vertical blow can reach a height of 9 m (30 ft.). Blue whales have 55-68 vertical grooves extending back almost to the navel. The dorsal fin is very small and set ¾ of the way back and the trailing edge of the flukes are smooth except for a small notch in the center.

FEMALE

Females tend to be slightly larger than males

SIZE:

For adults, a maximum of 33.5 m (110 ft.), but lengths of 21 m (70 ft.) are more common. Blue whale calves measure about 7 m (23 ft.) in length.

MALE

For Antarctic adults at physical maturity, lengths of 25 m (82 ft) are common; specimens from the Northern hemisphere are typically smaller

FEMALE

For Antarctic adults at physical maturity, lengths of 27 m (88.6 ft) are common; specimens from the Northern hemisphere are typically smaller

Calves are weaned at eight months, when they gain as much as 90 kg (200 lb.) a day

SEXUAL MATURITY:

At about 6-10 years of age

LIFE SPAN:

At least up to 30 years, possibly to well over 40 years

RANGE:

Oceans worldwide, most abundant in eastern north Pacific

HABITAT:

Primarily found along the edges of continental shelves and ice fronts

POPULATION:

GLOBAL

About 10,000-14,000

LOCAL

Off California, about 2,000

STATUS:

IUCN

Endangered

CITES

Appendix I

USFWS

Endangered

FUN FACTS

1.

Blue whales belong to the cetacean suborder Mysticeti - the baleen whales. Whales in this suborder lack teeth. Instead, they have stiff, hair-like baleen plates that hang from their upper jaws. With the baleen plates, blue whales filter vast quantities of krill (tiny shrimp-like crustaceans), consuming as much as four tons per day.

2.

Blue whales typically travel either singly or in pairs, although sometimes more whales may be found within close range in areas high in krill concentrations.

3.

Blue whales are capable of producing low-frequency sounds, which can travel hundreds of miles in deep water. The function of these long-ranging vocalizations is not quite known although it is theorized that some of the vocalizations aid in navigation by imaging seamounts, islands and other underwater masses.

4.

The blue whale is the largest animal in the world - probably the largest that ever lived. Long ago, Antarctic blue whales measured 30.5 m (100 ft.) and weighed 145,280 kg (320,000 lb.). Whale hunters took the most massive whales - the biggest blue whales today measure about 26 m (85 ft.), but lengths of 21 m (70 ft.) are more common. A blue whale's heart alone may weigh 908 kg (2,000 lb.), as much as a small car.

ECOLOGY AND CONSERVATION

Widespread commercial whaling during the 19th and 20th centuries, severely depleted blue whale populations. The current worldwide population is a fraction of the more than 200,000 blue whales that once roamed the seas.

Several U.S. and international treaties and agencies including the International Whaling Commission, the U.S. Marine Mammal Protection Act of 1972 and the U.S. Endangered Species Act of 1973 protect blue whales. But despite more than 50 years of protection, blue whale populations have not recovered.